Blockchain has been the buzz of healthcare IT lately, maybe even surpassing the status of FHIR. Momentum picked up for blockchain last year as the ONC announced a blockchain research challenge and announced  the winners in August 2016. So what exactly is blockchain?
Blockchain is a technology that keeps a permanent record of online transactions or exchanges. It was the foundation for trading the digital currency bitcoin, and has been around since 2009.
The permanent record can be shared among a network of computers. The records themselves are distributed among the network, rather than being stored locally. The name blockchain itself can be derived from the fact that (1) each transaction can be thought of as a block, and (2) a ledger of the transactions can be thought of as the chain.
There are many hopes and dreams of what blockchain can accomplish for health data interoperability. Some that are mentioned most often include:
- Elimination of the middleman, such as an Health Information Exchange (HIE) focuses on the mobilization of healthcare information electronically across organizations within a region or community. HIE provides the capability to electronically move clinical information between disparate health.... With all transactions kept in a ledger, the middleman is not needed to facilitate transactions. Eliminating the middleman can increase access to data on a large scale, further propelling the utilization of population health. Easier access to data can also increase efficiencies. Bruce Broussard, president and CEO of Humana, suggested blockchain will create greater efficiencies leading to lower administration costs for payers.
- Solving the master patient index (MPI) challenge. Tamara St. Claire, previous chief innovation officer at Conduent Health, in a presentation at HIMSS17, stated that the very nature of blockchain “actually incorporates MPI.” She said, “One way to think about it is the fact that not your identification but your data is hashed to the ledger. It’s an address you’re looking for. And there can be multiple addresses. And a patient can hold multiple keys to those addresses in their electronic wallet.”
- Combining data from multiple sources. Blockchain would have the ability to combine data regardless of the originating device, including mobile healthcare apps, wearables, home health devices, and EHRs.
The first two advantages involve moving data while keeping track of its source. Blockchain definitely seems to have unique features to solve healthcare IT challenges in this area. However, the last advantage deals not only with moving and tracking data, but in merging it together with unambiguous and shared meaning, often referred to semantic interoperability.
The merging of data brings to the surface additional questions. How will the payload be encoded in blockchain? Does healthcare still continue to use HL7 is a Standards Developing Organization accredited by the American National Standards Institute (ANSI) to author consensus-based standards representing a board view from healthcare system stakeholders. HL7 has compiled a collection of message form... V2, Clinical Document Architecture (CDA) HL7 CDA uses XML for encoding of the documents and breaks down the document in generic, unnamed, and non-templated sections. Documents can include discharge summaries, progress notes, history and physical reports,..., or even An HL7 standard that is short for Fast Healthcare Interoperability Resources and pronounced “Fire”. The standard defines a set of “Resources” that represent granular clinical concepts. The resources provide flexibility for a range of healthca... encoding? And, if so, how do we eliminate the mapping and vocabulary challenges that are so prevalent with traditional types of coding? I haven’t seen a good answer to this.
The ability to efficiently move lots of data around while maintaining patient identity would be a great lift to the healthcare IT industry. I hope blockchain can deliver on these challenges. But once the data gets where it is going, the challenge might still remain with piecing the data all together. HL7 FHIR  might help in this area with more consistent data records called resources, and just maybe the two big buzzwords of healthcare might be the ultimate solution together.